Light-emitting element, display module, lighting module, light-emitting device, display device, electronic device, and lighting device
A tandem light-emitting element in which generation of crosstalk can be suppressed even when the element is applied to a high-definition display is provided. In the tandem light-emitting element, a layer in contact the anode side of an intermediate layer contains 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen).
1. A light-emitting element comprising:
a first electrode;
an EL layer over the first electrode; and
a second electrode over the EL layer,
wherein the EL layer comprises a first light-emitting unit, a first layer, a first charge generation layer, a second light-emitting unit, a second layer, and a second charge generation layer,
wherein each of the first charge generation layer and the second charge generation layer comprises lithium,
wherein the first layer is provided between the first light-emitting unit and the first charge generation layer,
wherein the second layer is provided between the second light-emitting unit and the second charge generation layer, and
wherein the first layer and the second layer each comprise 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline.
2. The light-emitting element according to claim 1 , wherein the first charge generation layer comprises at least a charge generation region and an electron-injection buffer region.
3. The light-emitting element according to claim 2 , wherein an electron-relay region is provided between the charge generation region and the electron-injection buffer region.
4. The light-emitting element according to claim 2 , wherein the electron-injection buffer region comprises lithium.
5. The light-emitting element according to claim 1 ,
wherein the EL layer comprises a layer containing a condensed heteroaromatic compound,
wherein the layer containing a condensed heteroaromatic compound comprises iridium and a compound which comprises two nitrogen atoms in one condensed ring, and
wherein the layer containing a condensed heteroaromatic compound is in contact with the first layer.
6. The light-emitting element according to claim 5 ,
wherein the iridium is contained in part of the layer containing a condensed heteroaromatic compound and not contained in a region in contact with the first layer.
7. A light-emitting device comprising the light-emitting element according claim 1 and a unit configured to control the light-emitting element.
8. A display device comprising the light-emitting element according to claim 1 in a display portion and a unit configured to control the light-emitting element.
9. A lighting device comprising the light-emitting element according to claim 1 in a lighting portion and a unit configured to control the light-emitting element.
10. A light-emitting element comprising:
a first electrode;
an EL layer over the first electrode, the EL layer comprising:
a first light-emitting unit over the first electrode;
a first layer over the first light-emitting unit; and
a first charge generation layer over and in contact with the first layer, the first charge generation layer comprising lithium; and
a second electrode,
wherein the first layer comprises 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline.
11. The light-emitting element according to claim 10 , wherein the first charge generation layer comprises at least a charge generation region and an electron-injection buffer region.
12. The light-emitting element according to claim 11 ,
wherein an electron-relay region is provided between the charge generation region and the electron-injection buffer region.
13. The light-emitting element according to claim 11 , wherein the electron-injection buffer region comprises lithium.
14. The light-emitting element according to claim 10 ,
wherein the EL layer comprises a layer containing a condensed heteroaromatic compound,
wherein the layer containing a condensed heteroaromatic compound comprises iridium and a compound which comprises two nitrogen atoms in one condensed ring, and
wherein the layer containing a condensed heteroaromatic compound is in contact with the first layer.
15. The light-emitting element according to claim 14 , wherein the iridium is contained in part of the layer containing a condensed heteroaromatic compound and not contained in a region in contact with the first layer.
16. A light-emitting device comprising the light-emitting element according claim 10 and a unit configured to control the light-emitting element.
17. A display device comprising the light-emitting element according to claim 10 in a display portion and a unit configured to control the light-emitting element.
18. A lighting device comprising the light-emitting element according to claim 10 in a lighting portion and a unit configured to control the light-emitting element.
19. A light-emitting element comprising:
a first electrode;
an EL layer over the first electrode, the EL layer comprising:
a hole-injection layer over the first electrode;
a hole-transport layer over the hole-injection layer;
a light-emitting layer over the hole-transport layer;
an electron-transport layer over the light-emitting layer, the electron-transport layer comprising a first layer; and
a first charge generation layer over the electron-transport layer, the first charge generation layer comprising lithium; and
a second electrode over the first charge generation layer,
wherein the first layer comprises 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline.
20. The light-emitting element according to claim 19 , wherein the first charge generation layer comprises at least a charge generation region and an electron-injection buffer region.
21. The light-emitting element according to claim 20 , wherein an electron-relay region is provided between the charge generation region and the electron-injection buffer region.
22. The light-emitting element according to claim 20 , wherein the electron-injection buffer region comprises lithium.
23. The light-emitting element according to claim 19 ,
wherein the EL layer comprises a layer containing a condensed heteroaromatic compound,
wherein the layer containing a condensed heteroaromatic compound comprises iridium and a compound which comprises two nitrogen atoms in one condensed ring, and
wherein the layer containing a condensed heteroaromatic compound is in contact with the first layer.
24. The light-emitting element according to claim 23 , wherein the iridium is contained in part of the layer containing a condensed heteroaromatic compound and not contained in a region in contact with the first layer.
25. A light-emitting device comprising the light-emitting element according claim 19 and a unit configured to control the light-emitting element.
26. A display device comprising the light-emitting element according to claim 19 in a display portion and a unit configured to control the light-emitting element.
27. A lighting device comprising the light-emitting element according to claim 19 in a lighting portion and a unit configured to control the light-emitting element.